Syringe



R. w. OGLE Jan. 25, 1955 SQYRINGE Filed May 7} 19s?- 5 H mix M W M i 5y fin. R

United States Patent 2,700,386 SYRINGE Robert W. Ogle, Pasadena, Calif.

Application May 7, 1953, Serial No. 353,573

3 Claims. (Cl. 128-215) This invention relates to a disposable syringe and more particularly to a disposable plastic syringe having a steel cannula imbedded therein which is provided with novel means for sealing the open end of said cannula or needle.

In the copending application of Robert W. Ogle, Serial No. 235,807, filed July 9, 1951, there is shown a disposable plastic syringe for the same general purpose as the present invention but in which, for the sealing of the open end of the needle, there is provided means assuring that the open end of the needle will be imbedded in the plastic material forming the end of the needle cover when the needle cover is in place.

Experience has shown that in a very minor but still significant number of cases such arrangement will actually cause a core to be cut free from the plastic material which remains as a plug in the end of the needle when it is attempted to be used. The present invention has for its primary object the overcoming of this diificulty.

It is another object of this invention to provide a needle cover for a plastic syringe of the type described in which means is provided for accurately guiding the free end of the needle into the zone where it is intended to be sealed and which prevents any tendency for the needle to cut a path through the wall of the needle cover.

These and other objects and advantages of the present invention will be apparent from the annexed specification in which:

Figure 1 is a side elevation partly in section and with some parts broken away for clarity of illustration of a syringe embodying the present invention.

Figure 2 is an enlarged section taken along the line 22 of Figure 1.

Figure 3 is an enlarged fragmentary section similar to Figure 2.

Referring now more particularly to the drawings, the syringe comprises a hollow plastic barrel having an open end provided with a flange 11 and a closed end provided with an axially extending boss 12. As preferably designed, the closed end has a tapered wall 13 and a shoulder 14. The boss 12 at its free end is provided with a plurality of spaced longitudinally extending slots or recesses 15 which extend, as clearly shown in Figure 2, only a portion of the length of the boss. A needle cover 16 is provided in the form of a hollow generally tubular member provided with four stiffening ridges 17. The boss 12 receives under hoop tension the hollow needle 18 whiclzextends axially therefrom, as shown in Figures 1 an The needle cover 16 has a section indicated by the numeral 19 in which the internal diameter of the cover is uniform and preferably of diameter slightly less than the external diameter of the boss 12 so that, when the needle cover is received upon the boss 12, it will be received with a press fit accomplished by the elasticity of the polyethylene plastic material from which the needle cover is molded.

Above the section 19 the walls of the needle covering taper inwardly, as shown, at a gentle taper until toward the end of the needle cover the hollow passage therein approaches a point as indicated at 20. This hollow passage has a section indicated at 21 in which its internal diameter is less than the external diameter of the cannula or needle 18, and this section is sufiiciently long so as to cover the conventional beveled opening in the end of the needle.

The-needle cover 16 is so proportioned with respect to the needle 18 that, when it is fully seated upon the 2,700,386 Patented Jan. 25, 1955 shoulder 14, as shown in Figure 2, the free end of the needle will be received in the section 21 and completely enclosed fl1ereby. However, in assembling the syringe, prior to sealing the needle in such fashion, the needle cover is first placed on the boss 12 with the bottom end 22 thereof lying in the region of the slots 15 and failing to completely cover the same. In this condition a sterilizing gas can be blown into the interior of the needle cover 16 through the slots 15, thence through the open end of the needle 18 into the interior of the barrel 10. After such sterilizing, the needle cover is then fully seated on the shoulder 14, as shown in Figure 2.

The free end of the needle cover 16 is provided with an extension 23 having a male thread thereon adapted to be received when the needle cover is removed in the female threads of a rubber piston or plunger 24 which conventionally closes the open end of the barrel 10. The needle cover thus becomes part of the actuating plunger.

It has been found with disposable plastic syringes of the type described that the gently tapered walls of the needle cover 16 will accurately guide the open end of the needle into the desired space and will prevent the needle from cutting a path through the walls of the needle cover even if the needle should be out of alignment or bent. It has also been found in the use of the above-described device that the difiiculty of the needle cutting a plug from the polyethylene plastic material is entirely overcome.

While there has been described what is at present considered to be a preferred embodiment of the present invention, it will be appreciated by those skilled in the art that various changes and modifications can be made there in without departing from the essence of the invention, and it is intended to cover herein all such changes and modifications as come within the true spirit and scope of the appended claims.

Iclaim:

1. A syringe comprising: a hollow tubular member having an open end and a closed end; a boss formed on said closed end and extending outwardly in axial alignment with said tubular member; a hollow needle imbedded in said boss and said closed end communicating with said hollow tubular member and extending outwardly from said boss; a second hollow tubular member having an open end and a closed end, said open end being seated upon said boss with a press fit and sealing said boss; said hollow tubular members being formed of polyethylene plastic material; said second hollow tubular member having inwardly tapered walls converging to a section having an internal diameter less than the outer diameter of said needle and being proportioned with respect thereto so that when it is fully seated on said boss the open end of said needle is fully received within said section with a press fit and sealed thereby.

2. A syringe comprising: a hollow tubular member having an open end and a closed end; a boss formed on said closed end and extending outwardly in axial alignment with said tubular member; a hollow needle imbedded in said boss and said closed end communicating with said hollow tubular member and extending outwardly from said boss; a second hollow tubular member having an open end and a closed end, said open end being seated upon said boss with a press fit and sealing said boss; said hollow tubular members being formed of polyethylene plastic material; said second hollow tubular member having inwardly tapered walls converging to a section having an internal diameter less than the outer diameter of said needle and being proportioned with respect thereto so that when it is fully seated on said boss the open end of said needle is fully received within said section with a press fit and sealed thereby; said boss having a longitudinally extending slot for a portion only of its length.

3. A syringe comprising: a hollow tubular member having an open end and a closed end; a boss formed on said closed end and extending outwardly in axial alignment with said tubular member; a hollow needle imbedded in said boss and said closed end communicating with said hollow tubular member and extending outwardly from said boss; a second hollow tubular mernher having an open end and a closed end, said open end being seated upon said boss with a press fit and sealing said boss; said hollow tubular members being formed of polyethylene plastic material; said second hollow tubular member having inwardly tapered walls converging to a section having an internal diameter less than the outer diameter of said needle and being proportioned with respect thereto so that when it is fully seated on said boss the open end of said needle is fully received 1 within said section with a press fit and sealed thereby; said boss having a longitudinally extending slot for a portion only of its length; said second tubular member having an extension on its free end and a male thread carried by said extension.

References Cited in the file of this patent UNITED STATES PATENTS 2,497,562 Smith Feb. 14, 1950 FOREIGN PATENTS 570,186 Germany Feb. 13, 1933 

